Noncontacting electric power transfer apparatus, noncontacting signal transfer apparatus, split-type mechanical apparatus employing these transfer apparatus, and a control method for controlling same

Abstract

A noncontacting power transfer apparatus, a noncontacting signal transfer apparatus and a separate machine apparatus that uses these couplers are disclosed. The power coupler is composed of a primary side and a secondary side that are fixed to a static unit and rotatable unit of the machine apparatus, respectively, such that its output does not vary with arbitrary rotation by the rotatable unit. The signal coupler is composed of receiving side portion having a electric-to-light conversion device that converts an electric signal to an optical signal of rotational symmetry relative to the axis of rotation of the rotatable unit and a photoelectric conversion device that converts an optical signal to an electric signal. Accordingly, the rotatable unit can be supplied with power from the static unit even while rotating, and moreover, can communicate with the static unit. Further, the rotatable unit can be easily attached to the static unit and can be removed from the static unit.

What is claimed is: 
     
       1. A main-shaft-end information transmission apparatus for detecting tip information at the tip of the main shaft of a motor that rotates at high speed and transmitting the tip information to a static unit, comprising: sensor means installed on the main shaft for detecting and outputting the tip information;   power source means installed on the main shaft for rectifying a high-frequency alternating current and for providing a stabilized power supply to the sensor means;   a noncontacting power transfer apparatus for transmitting high-frequency power from said static unit to the power source means without direct electric contact; and   a noncontacting signal transfer apparatus for transmitting detection information detected by said sensor means to said static unit without direct electric contact, wherein said noncontacting signal transfer apparatus comprises;   electric-to-light conversion means fixed to a transmission side for converting an electric signal to be transmitted to optical signals distributed uniformly in all directions with respect to the axis of rotation of said main shaft; and   photoelectric conversion means fixed to a reception side for receiving an optical signal emitted by said electric-to-light conversion means and converting it to an electric signal.   
     
     
       2. The apparatus according to claim 1, wherein, when the tip information outputted by the sensor means is a digital signal, a first conversion means that converts the digital signal to a pulse train is provided on the main shaft; when the tip information is an analog signal, a second conversation means that converts the analog signal to the pulse train of a digital signal is provided on the main shaft; and the pulse train is transmitted to the static unit through a noncontacting signal transfer apparatus. 
     
     
       3. The apparatus according to claim 2 wherein the second conversion means is one of a pulse width modulation means, and the pulse width modulated wave is demodulated to an analog signal in the static unit, and a clock count digital measurement means for measuring the pulse width to provide the detected value of the tip information. 
     
     
       4. The apparatus according to claim 1 wherein the tip information to be detected is information necessary for one of measurement of the gap between a workpiece and a tool tip, or for remote measurement of a tool-tip protrusion of a infeed tool for variable boring radius. 
     
     
       5. The apparatus according to claim 1 wherein the tip information to be detected is information necessary for online surveillance of the state of general blade tools, particularly tip temperature information, vibration information, and acoustic emission information. 
     
     
       6. The apparatus according to claim 1 wherein the tip information to be detected is information necessary for feedback of a sequence signal, particularly a limit switch signal of an ATC collet chuck member. 
     
     
       7. The apparatus according to claim 1 wherein the tip information to be detected is information necessary for online monitoring of the grasping pressure acting on a workpiece in a main shaft tip chucking device and for closed loop control of chucking pressure. 
     
     
       8. The apparatus according to claim 1 wherein the tip information to be detected is information necessary for measurement physical values on the rotation shaft for measurement of shaft vibration values and rotor temperature. 
     
     
       9. A main-shaft-end information transmission apparatus for detecting tip information at the tip of the main shaft of a motor that rotates at high speed and transmitting the tip information to a static unit, comprising: sensor means installed on the main shaft for detecting the tip information;   power source means installed on the main shaft for rectifying a high-frequency alternating current and providing to the sensor means a stabilized power supply;   a noncontacting power transfer apparatus for transmitting high-frequency power from said static unit to the power source means without direct electric contact; and   a noncontacting signal transfer apparatus for transmitting detection information detected by said sensor means to said static unit without direct electric contact, wherein said noncontacting signal transfer apparatus comprises:   an electric-to-light conversion element fixed to the transmission side for converting an electric signal to be sent to an optical signal, and photoelectric conversion means fixed to the reception side for converting an optical signal emitted by the electric-to-light conversion element to an electric signal; and   the photoelectric conversion means having an incident plane distributed uniformly in all directions with respect to the axis of rotation of the rotatable unit, and the electric-to-light conversion element being located adjacent to the incident plane,   said transmission side being the side that transmits electric signals and said reception side being the side that receives those signals.   
     
     
       10. The apparatus according to claim 9, wherein, when the tip information outputted by the sensor means is a digital signal, a first conversion means that coverts the digital signal to a pulse train is provided on the main shaft; when the tip information is an analog signal, a second conversion means that converts the analog signal to the pulse train of a digital signal is provided on the main shaft; and the pulse train is transmitted to the static unit through said noncontacting signal transfer apparatus. 
     
     
       11. The apparatus according to claim 10, wherein the second conversion means is one of a pulse width modulation means, and the pulse width modulated wave is demodulated to an analog signal in the static unit, and a clock count digital measurement means for measuring the pulse width to provide the detected value of the tip information. 
     
     
       12. The apparatus according to claim 9, wherein the tip information to be detected is information necessary for one of measurement of the gap between a workpiece and a tool tip, and for remote measurement of a tool-tip protrusion of a infeed tool for variable boring radius. 
     
     
       13. The apparatus according to claim 9, wherein the tip information to be detected is information necessary for online surveillance of the state of general blade tools, particularly tip temperature information, vibration information, and acoustic emission information. 
     
     
       14. The apparatus according to claim 9, wherein the tip information to be detected is information necessary for feedback of a sequence signal, particularly a limit switch signal of an ATC collet chuck member. 
     
     
       15. The apparatus according to claim 9, wherein the tip information to be detected is information necessary for online monitoring of the grasping pressure acting on a workpiece in a main shaft tip chucking device and for closed loop control of chucking pressure. 
     
     
       16. The apparatus according to claim 9, wherein the tip information to be detected is information necessary for measurement of physical values on the rotation shaft for measurement of shaft vibration values and rotor temperature.